Ubiquitination of IQGAP1 regulates Cdc42
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Q Exactive
ORGANISM(S): Homo Sapiens (ncbitaxon:9606)
SUBMITTER: 
Craig Wagner
PROVIDER: MSV000084656 | MassIVE | Wed Dec 04 07:15:00 GMT 2019
REPOSITORIES: MassIVE
Similar Datasets
Project description:We here apply the COmbined FRActional DIagonal Chromatography (COFRADIC) technology to enrich for ubiquitinated peptides and identify sites of ubiquitination by mass spectrometry. Our technology bypasses the need to ectopically overexpress tagged variants of ubiquitin and the use of sequence-biased antibodies recognizing ubiquitin remnants. In brief, all protein primary amino groups are blocked by chemical acetylation after which ubiquitin chains are proteolytically and specifically removed by the catalytic core domain of the USP2 deubiquitinase (USP2cc). As USP2cc cleaves the isopeptidyl bond between the ubiquitin C-terminus and the ?-amino group of the ubiquitinated lysine, this enzyme re-introduces primary ?-amino groups in proteins. These amino groups are then chemically modified with a handle that allows specific isolation of ubiquitinated peptides during subsequent COFRADIC chromatographic runs. Our method allowed us to identify over 8,200 endogenous ubiquitination sites in more than 3,600 different proteins in a native human Jurkat cell lysate.
2017-03-29 | MSV000080780 | MassIVE
Project description:The reversible attachment of ubiquitin governs the interaction, activity and degradation of proteins whereby the type and target of this conjugation determine the biological response. The investigation of this complex and multi-faceted protein ubiquitination mostly relies on painstaking biochemical analyses. Here, we employ recombinant binding domains to identify the UHRF1 dependent ubiquitinated proteins by liquid chromatography tandem mass spectrometry (LC-MS/MS).
2023-01-30 | PXD034335 | Pride
Project description:Viruses promote infection by hijacking the host ubiquitin machinery to counteract or redirect cellular processes. Adenovirus encodes two early proteins, E1B55K and E4orf6, that together co-opt a cellular ubiquitin ligase complex to overcome host defenses and promote virus production. Adenovirus mutants lacking E1B55K or E4orf6 display defects in viral RNA processing and protein production, but previously identified substrates of the ligase do not explain these phenotypes. Here we used a quantitative proteomics approach to identify substrates of E1B55K/E4orf6 that are ubiquitinated to facilitate RNA processing. While cellular proteins known as substrates of E1B55K/E4orf6 are degraded by the proteasome, we uncovered RNA-binding proteins (RBPs) as high-confidence substrates which are not decreased in overall abundance. We focused on two predominant RBPs, RALY and hnRNP-C, which we confirm are ubiquitinated without degradation. Knockdown of RALY and hnRNP-C rescued levels of viral RNA splicing, protein, and progeny production during infection with E1B55K-deleted virus. Furthermore, deletion of E1B55K resulted in increased interaction of hnRNP-C with viral RNA and attenuation of viral RNA processing. These data suggest viral-mediated ubiquitination of RALY and hnRNP-C relieves a restriction on viral RNA processing, revealing an unexpected role for non-degradative ubiquitination in the manipulation of cellular processes during virus infection.
2020-07-09 | GSE145411 | GEO
Project description:We here apply the COmbined FRActional DIagonal Chromatography (COFRADIC) technology to enrich for ubiquitinated peptides and identify sites of ubiquitination by mass spectrometry. Our technology bypasses the need to ectopically overexpress tagged variants of ubiquitin and the use of sequence-biased antibodies recognizing ubiquitin remnants. In brief, all protein primary amino groups are blocked by chemical acetylation after which ubiquitin chains are proteolytically and specifically removed by the catalytic core domain of the USP2 deubiquitinase (USP2cc). As USP2cc cleaves the isopeptidyl bond between the ubiquitin C-terminus and the ɛ-amino group of the ubiquitinated lysine, this enzyme re-introduces primary ɛ-amino groups in proteins. These amino groups are then chemically modified with a handle that allows specific isolation of ubiquitinated peptides during subsequent COFRADIC chromatographic runs. Our method allowed us to identify over 8,200 endogenous ubiquitination sites in more than 3,600 different proteins in a native human Jurkat cell lysate.
2016-07-08 | PXD000934 | Pride
Project description:Translation elongation stalling has the potential to produce toxic truncated protein fragments. Translation of either non-stop mRNA or transcripts coding for poly-basic sequences induces ribosome stalling, and the arrest product is degraded by the ribosome-mediated quality control (RQC) system. During this process, the stalled ribosome is dissociated into subunits, and the polypeptide is ubiquitinated by the E3 ubiquitin ligase Listerin on the 60S large ribosomal subunit, leading to subsequent proteasomal degradation. However, it is largely unknown how the specific stalled ribosomes are recognized as aberrant to engage the RQC system. Here, we report that ubiquitination of the ribosomal protein uS10 of the 40S small ribosomal subunit, by the E3 ubiquitin ligase Hel2 (or RQC-trigger (Rqt) 1) initiates RQC. We identified a novel RQC-trigger (RQT) complex composed of the RNA helicase-family protein Slh1/Rqt2, the ubiquitin binding protein Cue3/Rqt3, and yKR023W/Rqt4 that is required for RQC. The defects in RQC of the RQT mutants correlated with sensitivity to anisomycin, which stalls ribosome at the rotated form, suggesting that RQT factors rescue ribosomes stalled by this drug. Our un-biased survey by ribosome profiling revealed that ribosomes stalled at the rotated state with specific pairs of codons at P-A sites serve as RQC substrates. Rqt1 specifically ubiquitinates these arrested ribosomes to target them to the RQT complex, allowing subsequent RQC reactions including dissociation of the stalled ribosome into subunits. Our results provide mechanistic insight into the surveillance system for aberrant proteins induced by ribosome stalling and mediated by ribosome ubiquitination.
2017-07-31 | GSE90919 | GEO
Project description:Proctor2007 - Age related decline of proteolysis, ubiquitin-proteome system
This
is a stochastic model of the ubiquitin-proteasome system for a
generic pool of native proteins (NatP), which have a half-life of
about 10 hours under normal conditions. It is assumed that these
proteins are only degraded after they have lost their native
structure due to a damage event. This is represented in the model
by the misfolding reaction which depends on the level of reactive
oxygen species (ROS) in the cell. Misfolded proteins (MisP) are
first bound by an E3 ubiquitin ligase. Ubiquitin (Ub) is
activated by E1 (ubiquitin-activating enzyme) and then passed to
E2 (ubiquitin-conjugating enzyme). The E2 enzyme then passes the
ubiquitin molecule to the E3/MisP complex with the net effect
that the misfolded protein is monoubiquitinated and both E2 and
E3 are released. Further ubiquitin molecules are added in a
step-wise manner. When the chain of ubiquitin molecules is of
length 4 or more, the polyubiquitinated misfolded protein may
bind to the proteasome. The model also includes de-ubiquitinating
enzymes (DUB) which cleave ubiquitin molecules from the chain in
a step-wise manner. They work on chains attached to misfolded
proteins both unbound and bound to the proteasomes. Misfolded
proteins bound to the proteasome may be degraded releasing
ubiquitin. Misfolded proteins including ubiquitinated proteins
may also aggregate. Aggregates (AggP) may be sequestered
(Seq_AggP) which takes them out of harm's way or they may bind to
the proteasome (AggP_Proteasome). Proteasomes bound by aggregates
are no longer available for protein degradation.
Figure
2 and Figure 3 has been simulated using Gillespie2.
This model is described in the article:
An in silico model of the
ubiquitin-proteasome system that incorporates normal
homeostasis and age-related decline.
Proctor CJ, Tsirigotis M, Gray
DA.
BMC Syst Biol 2007; 1: 17
Abstract:
BACKGROUND: The ubiquitin-proteasome system is responsible
for homeostatic degradation of intact protein substrates as
well as the elimination of damaged or misfolded proteins that
might otherwise aggregate. During ageing there is a decline in
proteasome activity and an increase in aggregated proteins.
Many neurodegenerative diseases are characterised by the
presence of distinctive ubiquitin-positive inclusion bodies in
affected regions of the brain. These inclusions consist of
insoluble, unfolded, ubiquitinated polypeptides that fail to be
targeted and degraded by the proteasome. We are using a systems
biology approach to try and determine the primary event in the
decline in proteolytic capacity with age and whether there is
in fact a vicious cycle of inhibition, with accumulating
aggregates further inhibiting proteolysis, prompting
accumulation of aggregates and so on. A stochastic model of the
ubiquitin-proteasome system has been developed using the
Systems Biology Mark-up Language (SBML). Simulations are
carried out on the BASIS (Biology of Ageing e-Science
Integration and Simulation) system and the model output is
compared to experimental data wherein levels of ubiquitin and
ubiquitinated substrates are monitored in cultured cells under
various conditions. The model can be used to predict the
effects of different experimental procedures such as inhibition
of the proteasome or shutting down the enzyme cascade
responsible for ubiquitin conjugation. RESULTS: The model
output shows good agreement with experimental data under a
number of different conditions. However, our model predicts
that monomeric ubiquitin pools are always depleted under
conditions of proteasome inhibition, whereas experimental data
show that monomeric pools were depleted in IMR-90 cells but not
in ts20 cells, suggesting that cell lines vary in their ability
to replenish ubiquitin pools and there is the need to
incorporate ubiquitin turnover into the model. Sensitivity
analysis of the model revealed which parameters have an
important effect on protein turnover and aggregation kinetics.
CONCLUSION: We have developed a model of the
ubiquitin-proteasome system using an iterative approach of
model building and validation against experimental data. Using
SBML to encode the model ensures that it can be easily modified
and extended as more data become available. Important aspects
to be included in subsequent models are details of ubiquitin
turnover, models of autophagy, the inclusion of a pool of
short-lived proteins and further details of the aggregation
process.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000105.
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To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
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2024-09-02 | BIOMD0000000105 | BioModels
Project description:Post-translational modification of amino acids changes the properties of a protein and increases the functional diversity of the proteome. For example, protein ubiquitination influences almost all cellular processes and can remodel the proteome in a matter of minutes. However, mostly due to technical limitations, global profiling of the plant ubiquitinome and proteome-wide identification of specific ubiquitinated residues remains challenging. Here, we made use of the COFRADIC technology to map ubiquitination sites in Arabidopsis thaliana. Across two biological replicates, we identified a total of 3,009 ubiquitination sites in 1,607 proteins. Our data increases the number of reported ubiquitin conjugation sites in Arabidopsis by a factor of 10. It contains well-known ubiquitination targets, including cell cycle proteins and key transcriptional regulators of phytohormone signaling as well as yet unreported targets, such as the Glutaredoxin S17 for which we provide here evidence of proteasomal degradation Finally, we could detect N-terminal ubiquitin conjugation on 19 proteins, a less commonly described type of protein modification.
2016-08-08 | PXD002297 | Pride
Project description:Genome wide screens identified negative genetic interactions between several cofactors of the exosome nuclease complex and the Bre5-Ubp3 ubiquitin protease complex. RNA-binding was shown for Bre5 with enrichment for sites over exon 2 of spliced pre-mRNAs and close to poly(A) sites. An inducible splicing-reporter showed a requirement for Bre5 in efficient in vivo splicing and for normal RNAPII elongation, specifically on splicing-competent genes. A Bre5-Ubp3 sensitive site of RNAPII ubiquitination was mapped at Lys1246 at the entrance to the active site of the large subunit. Ubiquitinated RNAPII was depleted at the TSS but enriched at the 5’ end of exon 2 and upstream of poly(A) sites, similar to Bre5. Mutation of Lys1246 reduced RNAPII occupancy upstream of the poly(A) site, consistent with reduced pausing at a potential surveillance site, but increased RNAPII residence downstream of the poly(A) site. Strains expressing RNAPII with the Lys1246 mutation showed increased levels of unspliced but poly(A)+ RNA, indicating reduced cotranscriptional splicing efficiency. We propose that ubiquinitation of RNAPII is induced by RNA processing events and linked to transcriptional pausing, which is released by Bre5-Ubp3 associated with the nascent transcript.
2017-10-22 | GSE94941 | GEO
Project description:Xylem vessels function in the long-distance conduction of water in land plants. The NAC transcription factor VASCULAR-RELATED NAC-DOMAIN7 (VND7) is a master regulator of xylem vessel cell differentiation in Arabidopsis (Arabidopsis thaliana). We previously isolated seiv (suppressor of ectopic xylem vessel cell differentiation induced by VND7) mutants, which are suppressor mutants of VND7-inducible xylem vessel cell differentiation. Here, we report that the responsible genes for seiv3, seiv4, seiv6, and seiv9 are protein ubiquitination-related genes encoding PLANT U-BOX46 (PUB46), uncharacterized F-BOX protein, PUB36, and UBIQUITIN-SPECIFIC PROTEASE1, respectively. We also found the decreased expression of genes downstream of VND7 and abnormal xylem transport activity in the seiv mutants. Upon VND7 induction, ubiquitinated levels from 492 and 180 protein groups were up- and down-regulated, respectively. Proteins for cell wall biosynthesis and protein transport were ubiquitinated by the VND7 induction, whereas such active protein ubiquitination was not observed in the seiv mutants. We detected the ubiquitination of three lysine residues in VND7: K94, K105, and K260. Substituting K94 with arginine significantly decreased the transactivation activity of VND7, suggesting that the ubiquitination of K94 is crucial for regulating VND7 activity. Our findings highlight the crucial roles of target protein ubiquitination in regulating xylem vessel activity.
2024-10-17 | PXD048830 | Pride
Project description:Cryptococcus neoformans poses a great threat to human communities, given that it quickly becomes resistant to available antifungal drugs. Herein, a conserved chromatin remodeler, Isw1, is shown to function as a master transcriptional modulator of genes responsible for multidrug resistance. It reciprocally controls drug resistance, and cells with disrupted ISW1 demonstrate profound resistance to fluconazole, ketoconazole, 5-fluorocytosine and 5-fluorouracil. Mass spectrometry reveals that Isw1 is both acetylated and ubiquitinated. These two protein posttranslational modifications confer an interplay regulation mechanism that controls Isw1 protein degradation via a ubiquitin-mediated proteasome and, consequently, C. neoformans resistance to drugs. Functional mutagenesis analysis of acetylation and ubiquitination sites reveals that the acetylation status of the lysine 97 residue on Isw1 coordinates its ubiquitination processes at lysines 113 and 441 by modulating the protein interactions between Isw1 and Cdc4, an E3 ligase. Clinical C. neoformans isolates overexpressing the undegradable ISW1 mutant demonstrate impaired drug-resistant phenotypes. Collectively, our studies reveal a sophisticated acetylation-Isw1-ubiquintation regulation axis that controls multidrug resistance in fungal pathogens.
2022-11-10 | GSE217187 | GEO